Cooled turbomachinery components

• US 5,062,768 A
• Filed: 04/29/1991
• Issued: 11/05/1991
• Est. Priority Date: 12/23/1988
• Status: Expired due to Term

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: Marriage, Peter V.
• Primary Examiner(s): KWON, JOHN
• Application Number:
  US07/693,014
• Time in Patent Office: 190 Days
• Field of Search: 416/96 R, 416/97 R, 415/115, 415/116, 29/889.721, 408/1 R
• US Class Current: 416/97.00R
• CPC Class Codes: F01D 5/186 Film cooling F01D5/187 takes precedence
• CPC Class Codes: F05D 2260/607 Preventing clogging or obstruction of flow paths by dirt, dust, or foreign particles
• CPC Class Codes: Y10T 29/49341 with cooling passage

Abstract

An aerofoil for a gas turbine engine turbine rotor blade or stator vane is subject to film cooling by multiple rows of small cooling air exit apertures in the exterior surface of the blade or vane. Each exit aperture is supplied with cooling air through at least two holes extending from the aperture through the wall of the blade or vane to interior chambers or passages. The holes are mutually intersecting and their intersection forms the exit apertures and defines a flow constriction for controlling the flow rate of cooling air through the holes and out of the aperture. If the holes'"'"' centerlines intersect behind the plane of the exterior surface by an optional distance, the flow constriction is spaced apart from the exit aperture and is within the wall thickness, the exit aperture being enlarged. These film cooling hole configurations reduce the liability of the holes to block up due to contamination by environmental debris.

Claims

1. A film-cooled component having wall means comprising a first surface subject to heating by flow of hot fluid therepast and a second surface subjected to cooling by flow of pressurized coolant therepast, the first surface having a plurality of small coolant exit apertures therein connected to the second surface by cooling hole structures extending through the wall means, whereby coolant exits from said apertures onto the first surface for film-cooling of the same, each cooling hole structure comprising in flow series a plurality of coolant entry apertures in said second surface, a flow constriction and one of said exit apertures connected only to said one flow constriction, each cooling hole structure being a plurality of substantially straight mutually intersecting holes which share said flow constriction and said exit aperture, each cooling hole structure being separated by a portion of said wall means from each other cooling hole structure so that said cooling hole structures are unconnected to one another, said flow constriction comprising the intersection of said holes and said exit aperture being formed adjacent said intersection, said flow constriction being of smaller flow are than said exit aperture.

2. A film-cooled component according to claim 1, in which each exit aperture is connected to the second surface by two mutually intersecting holes.

3. A film-cooled component according to claim 1, in which each exit aperture is connected to the second surface by three mutually intersecting holes.

4. A film-cooled component according to claim 1 in which the longitudinal centerlines of the intersecting holes intersect at a common point.

5. A film-cooled component according to claim 1 in which each hole has substantially similar obliquity with respect to the first surface.

6. A film-cooled component according to claim 1 in which the holes have unequal obliquities with respect to the first surface.

7. A film-cooled component according to claim 1 in which the longitudinal centerlines of the holes occupy a single plane.

8. A film-cooled component according to claim 7 in which the single plane containing the longitudinal centerlines is obliquely oriented with respect to the first surface.

9. A film-cooled component according to claim 1 comprising a turbine aerofoil for a gas turbine engine.

10. A method for producing a film-cooled component, the component having wall means comprising a first surface subject to heating by flow of hot fluid therepast and a second surface subject to cooling by flow of pressurized coolant therepast, the method comprising drilling a plurality of groups of film-cooling holes through the wall means to connect the first surface to the second surface, the members of each group of holes being drilled sequentially with different but crossing orientation with respect to each other such that they penetrate the first surface in overlapping fashion to form a common coolant exit aperture and intersect each other to form a flow constriction for controlling the flow rate of coolant out of the common exit aperture, said flow constriction being of smaller flow area than said exit aperture, and including the step of maintaining the members of each group having a common coolant exit aperture separated from the members of each other group associated with a different exit aperture.

11. A method according to claim 10 in which two holes are drilled to form each exit aperture.

12. A method according to claim 10 in which three holes are drilled to form each exit aperture.

13. A film-cooled component produced by the method of claim 10.